Not applicable.
Not applicable.
The present invention relates to a system and method for controlling the position of an implement associated with a work vehicle (such as an agricultural work vehicle such as a tractor or a planter pulled by a tractor) and the position(s) of one or more markers attached to the implement. More particularly, the present invention relates to a system and method for controlling the positions of an implement and one or more markers by which it is possible to both provide coordinated positioning in which the markers and implement move together and independent positioning in which the markers and implement can be moved independently of one another.
It is known for agricultural work vehicles, such as tractors or combines or other agricultural harvesting machines, to tow implements that perform (or include tool bar(s) that perform) one or more functions, such as plowing, planting or seeding, fertilizing, and harvesting in a field. Also, it is known for agricultural work vehicles to employ one, two or more markers that typically are extendable beyond the perimeter of the work vehicle and create markings by, for example, gouging furrows in the field adjacent to the vehicle. Such markers are typically attached to the implement towed by the work vehicle, although they may be attached to the work vehicle itself. Since an agricultural work vehicle typically traverses a field in a systematic row-by-row format, the markers often are used to create markings in the field to indicate to the operator of the vehicle a path for the next row. Markers are often, though not necessarily, installed in pairs on both sides of an agricultural work vehicle. Also, some agricultural work vehicles include more than one marker that can extend from a given side of the vehicle. For example, an agricultural work vehicle can include both inner and outer markers, where the outer markers are employed to provide markings at relatively larger distances from the work vehicle, and the inner markers are employed to provide markings at relatively smaller distances from the work vehicle.
With respect to most agricultural work vehicles, it is necessary for the work vehicles to have the capability of raising and lowering the implements (or tool bars of the implements) and markers with respect to the work vehicles and the ground. For example, a typical agricultural work vehicle proceeding through a field in a row-by-row manner must turn around at the end of each row in order to proceed down the successive row. While turning around, it is sometimes appropriate to raise the implement (or the tool bar of the implement) towed by the agricultural work vehicle some distance above the ground to prevent the implement from acting upon (or damaging) the ground or crops outside the lines of the rows. Similarly, it is common that the markers attached to an implement of a work vehicle be raised some distance above the ground while the work vehicle is turning around to prevent improper marking, damage to the ground or crops, or damage to the markers themselves that might occur if the markers encountered obstacles such as fences, trees, and boulders.
Often it is necessary not only that the markers themselves be raised but also that the implementation of the markers be changed while the work vehicle is turning around. For example, while it may be appropriate to utilize markers on both sides of a work vehicle as it first enters and makes its initial crossing of a field so as to create row markings on both sides of the work vehicle, implementation of markers on both sides of the work vehicle is no longer appropriate once it has completed its first row. Instead, it is then appropriate to utilize a marker only on one side of the work vehicle so that, as the vehicle proceeds down one of the two paths marked during its initial crossing of the field, a new row marking parallel to the previous row markings is created only in that section of the field that has not yet been traversed by the work vehicle. Insofar as a work vehicle needs to turn around regularly as it advances row-by-row through a field, it is appropriate to alternate the implementation of the markers used to create row markings so that new row markings are always created in that section of the field that has not yet been traversed by the work vehicle.
Because it is often appropriate for the markers and implement/tool bar of an agricultural work vehicle to raised and lowered at the same time, some conventional agricultural work vehicles actuate the raising and lowering of their markers and implements/tool bars using the same hydraulic valve. Such a single-valve system is simple and inexpensive to install on an agricultural work vehicle. However, in some agricultural work vehicles, it is desirable to have the capability of controlling the raising and lowering of markers independently of the raising and lowering of the implements/tool bars. For example, in the case of planters, it often is desirable to have the capability of raising and lowering markers, for reasons such as those discussed above (e.g., to avoid damage to the markers), without simultaneously raising and lowering the implements/tool bars of the planters, which would interrupt the planting operation. Some conventional planters, as well as other conventional agricultural work vehicles that need to provide such independent control of the markers and implements/tool bars, provide such independent control through the use of two (or more) different hydraulic valves for separately actuating the different devices.
Although such conventional systems employing multiple hydraulic valves allow for independent control of the markers and implements/tool bars, the systems can be difficult to manually operate. In particular, in situations where an operator desires coordinated movement of both the markers and implements/tool bar, the operator must manually actuate both (or all) of the hydraulic valves in order to obtain the desired functional adjustments. Such simultaneous actuation of multiple valves can require considerable attention and coordination on the part of the operator. Therefore, while the use of multiple hydraulic valves in a conventional agricultural work vehicle allows for independent control of the markers and implement/tool bar, it complicates achieving simultaneous movement of the markers and implement/tool bar that would otherwise be simple to achieve in agricultural work vehicles employing only a single hydraulic valve.
Accordingly, it would be advantageous if a new system and method were developed for implementation in an agricultural work vehicle that made it possible to control the positions of the vehicle""s markers and implement/tool bar both simultaneously and independently of one another. In particular, it would be advantageous if, by way of such a new system and method, it was possible for an operator to achieve simultaneous raising and/or lowering of both the markers and the implement/tool bar of an agricultural work vehicle without having to simultaneously, manually actuate multiple different hydraulic valves, yet also possible to achieve independent control of the markers and implement/tool bar.
These and other aspects of the invention will become apparent from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention and reference is made therefore, to the claims herein for interpreting the scope of the invention.
In particular, the present invention relates to an apparatus for controlling positions of at least a portion of an implement and a first marker, both of which are associated with a work vehicle. The apparatus includes a hydraulic circuit coupled to a first cylinder that governs the position of the first marker, a first hydraulic valve coupled to a second cylinder that governs the position of the portion of the implement and also coupled to a first port of the hydraulic circuit, and a second hydraulic valve coupled to a second port of the hydraulic circuit. The hydraulic circuit is configured to isolate the first port of the hydraulic circuit from secondary hydraulic pressure supplied to the second port by way of the second hydraulic valve, and further configured to isolate the primary port of the hydraulic circuit from primary hydraulic pressure supplied to the first port by way of the first hydraulic valve. The primary hydraulic pressure is capable of producing changes in the positions of both the portion of the implement and the first marker in a coordinated manner, and the second hydraulic pressure is capable of producing changes in the position of the first marker independently of the position of the portion of the implement.
The present invention further relates to a work vehicle assembly that includes at least one marker that is capable of being raised and lowered at least in part by way of a first hydraulic cylinder, a component of the work vehicle assembly that is capable of being raised and lowered at least in part by way of a second hydraulic cylinder, and a hydraulic circuit having first and second ports and further coupled to the first hydraulic cylinder. The work vehicle assembly further includes a hydraulic fluid pressure source, a hydraulic fluid reservoir, and first and second control valves, each of which is coupled between a respective one of the first and second ports and both of the hydraulic fluid pressure source and the hydraulic fluid reservoir, where the first control valve additionally is coupled to the second hydraulic cylinder. The hydraulic circuit includes means for isolating the first port from secondary hydraulic pressure applied to the second port by way of the second control valve, and for isolating the second port from primary hydraulic pressure applied to the first port by way of the first control valve. Additionally, the primary hydraulic pressure communicated by way of the first control valve is capable of producing changes in the positions of both the first and second hydraulic cylinders, and the secondary hydraulic pressure communicated by way of the second control valve is capable of producing changes in the position of the first hydraulic cylinder but not the second hydraulic cylinder.
The present invention additionally relates to a method of controlling positions of at least one portion of an implement and at least one marker on a work vehicle assembly. The method includes providing primary hydraulic pressure by way of a first control valve to both a first cylinder and a first port of a hydraulic circuit that in turn is coupled to a second cylinder, where the first and second cylinders respectively govern the positions of the portion of the implement and the at least one marker, respectively, and where the providing of the primary hydraulic fluid adjusts the positions of both the portion of the implement and the at least one marker. The method further includes preventing the primary hydraulic pressure from being communicated, while it is being provided to the first port of the hydraulic circuit, to a second port of the hydraulic circuit, and providing secondary hydraulic pressure by way of a second control valve to the second port of the hydraulic circuit, where the providing of the secondary hydraulic pressure adjusts the position of the at least one marker. The method additionally includes preventing the secondary hydraulic pressure from being communicated, while it is being provided to the second port of the hydraulic circuit, to the first port of the hydraulic circuit.